Fuel Filler Cap: Description and Operation

FEATURES
The fuel tank filler cap has the following characteristics:
- A vacuum valve allows air into the fuel tank to replace fuel as it is used and opens after a vacuum of -3.4 kPa (-0.5 psi).

- A pressure valve acts as a backup pressure relief valve if venting system is over pressurized or restricted. The pressure relief is 11 kPa (1.6 psi).

- Damage to the fuel tank filler caps or contamination that stops the pressure vacuum from working may result in deformation of the fuel tank. Care should be taken to use a proper fuel tank filler cap in good working order.

- The fuel tank filler cap is a threaded screw-on design with a pre-vent feature that allows the fuel tank to vent for the first three-quarter turn before unthreading.

- Fuel tank filler caps are attached to the vehicle with a strap using the filler pipe-to-housing screw at the three to four o'clock position.

- The fuel tank filler cap provides pressure and vacuum relief functions and should be replaced with the proper pressure/vacuum relief fuel tank filler cap to prevent possible system malfunction.

- The fuel tank filler cap is fitted with a torque-limiting ratchet to ease in removal.

- When installing the fuel tank filler cap, continue to turn clockwise until ratchet mechanism give off three or more loud "clicks".